Fe Ni fixed expansion alloy is a series of constant expansion alloys which can match soft glass and ceramics with different expansion coefficient in a given temperature range by adjusting nickel content. Its expansion coefficient and Curie point increase with the increase of nickel content
The heat treatment system of expansion coefficient performance test sample specified in the standard is: heating to 850 ℃± 20 ℃ in protective atmosphere or vacuum, holding for 1h, cooling to below 400 ℃ at the speed of no more than 300 ℃ / min.
Specification and supply status of 4j52
The varieties are bar, tube, plate, strip and wire.
Melting and casting process of 4j52
Smelting in non vacuum induction furnace, vacuum induction furnace or electric arc furnace.
Application and special requirements of 4j52
4j52 is a typical brand of glass sealing alloy. It has been used in aviation factory for a long time with stable performance.
4j52 alloy is mainly used for sealing with soft lead glass, small electronic tube lead.
In application, the selected sealing material should match the expansion coefficient of the alloy. The grain size should be controlled during heat treatment to ensure good deep drawing properties. When forging and rolling materials are used, the air tightness of materials shall be strictly inspected.